HMNS boasts one of the finest collections of trilobites in the world. Though they ruled the sea-bottom for a quarter of a billion years, trilobites suffered a total extinction before the opening of the Mesozoic Era, 250 million years ago.

“Happy Puppy” -- Coal Age Frog-oid

Sclerocephalid or archegosaurid amphibian, Early Permian, c. 290 million years BP, Germany

Our “happy puppy” fossil is unique, the best specimen found of this new species. The most ancient amphibians had body armor of bone scales, covering top, sides, and even the belly. Extra thick bone provided a breastplate protecting heart and lungs.

This is one of the most beautiful, yet poignant, skeletons of an ocean-going reptile ever found. The elegantly streamlined ichthyosaur is preserved with every bone in place, plus remnants of the skin. And....seven unborn babies.

“Cretaceous Taz”

Didelphodon vorax, Late Cretaceous, c. 66 million years ago, Wyoming and Montana

HMNS has the only skeleton in the world of the most ferocious furball that lived with T. rex and Triceratops and the other members of the final dinosaur community. Pound for pound, “Cretaceous Taz” was the most powerful creature of river and lake - the terror of clams, snails, and baby alligators.

“Bullet-proof Alligator Gar”

Atractosteus atrox, Eocene, c. 49 million years BP, Wyoming

Our complete skeleton is from a huge species that was the apex predator in sluggish rivers, 49 million years ago. The specimen shows every one of the double-layered armored scales that were knit so tightly together that the fish had nothing to fear from a crocodile’s jaws.

“Super-Soft-shelled Turtle” -- Living fossil in a half-shell

Trionychid turtle, Eocene, c. 49 million years BP, Wyoming

This specimen comes from the Green River beds, 49 million years old. The bone plates along the edge of the shell, normally thick and heavy, are gone entirely. The bottom shell, too, is reduced to a fraction of the standard turtle pattern. Result: lighter skeleton and the fastest swimming stroke in lakes and rivers.

“King of the Sharks” -- the Megalodon

Carcharocles megalodon, Miocene, c. 19 million years BP, Florida

The largest jaw ever assembled of the stupendous Megalodon shark, a fish twice as long as the largest known great white shark. “Meg” teeth were whale-choppers. Each tooth carried a fine, saw-toothed edge and a thick central zone.

“Slothzilla”

Eremotherium eomigrans, Late Ice Age (Pleistocene), c. 30,000 years BP, North Carolina

HMNS has one of the largest mounted skeletons of a giant ground sloth anywhere. Eremotherium was as heavy as a bull elephant, had hide protected with chain-mail armor made of bone, and carried arms as strong as a dozen grizzlies put together. The great sloth could grab an unwary saber-toothed cat and hurl it fifteen yards.